3.7. Controlling Virtual Hosts on Win32

The Win32 version of Apache runs a
parent version of the code and a single multi-threaded child that
handles all requests.

3.7.1. ThreadsPerChild

ThreadsPerChild number
Default number: 50
Server config

Currently this directive is only relevant to Win32. You may need to
increase this number from 50, the default, if your site gets a lot of
simultaneous hits. The name ThreadsPerChild may
suggest that there can be more than one child process in a Win32
installation, but this is not currently the case.[32]

[32]If
you really want to know: Win32 will not distribute requests among
multiple children like Unix does. The first process to open a port
gets all the connections, whether it is ready for them or not.
Microsoft claims this is a Good Thing. We're not so
sure.